As the need for increased data storage changes, the search for higher density, faster access memory technologies also increases. One of these, holographic data storage, provides the promise for increased access to higher density data. The techniques for realizing such storage typically utilize some type of storage media, such as photorefractive crystals or photopolymer layers, to store 3-D "stacks" of data in the form of pages of data. Typically, coherent light beams from lasers are utilized to perform the addressing, writing and reading of the data from the storage media by directing these beams at a specific region on the surface of the media. Writing is achieved by remembering the interference pattern formed by these beams at this region. Reading is achieved by detecting a reconstructed light beam as it exits the storage media, the data then being extracted therefrom. Addressing is achieved by the positioning of the laser beams, and this is typically done through the mechanical movement of mirrors or lenses; however, the storage media itself can be moved relative to fixed laser beams.
Heretofore, when utilizing a holographic storage media, it is typically secured in a more or less permanent fashion to a mounting structure which either has some type of positioning mechanism that allows the media to be positioned, or is fixed wherein the optics determines the position. The disadvantage to this is that the layout of the system is such that the media is not easily accessible for replacement thereof. It is desirable that holographic storage medias utilizing a photopolymer material, and therefore operate as a Write-Once Read-Many (WORM) media, be designed to be "removable" and "portable" similar to a floppy disk. As such, they must be contained in some type of carrier, which carrier can be removed. However, design of this carder is not straightforward, as it must provide structural stability, not add significantly to the media package, give the media protection and isolate the media from premature exposure. There is also a desire to provide for some type of fiduciary marking to provide position information and possibly make some provision for containing information as to usage history. Present media do not provide for this.